On September 10 at 9am CEST, the first test of the most controversial experiment of the century was held in Geneva, Switzerland. The Large Hadron Collider (LHC) is, simply, the largest particle accelerator ever built, a massive scientific achievement dedicated to unveiling obscurities in our modern conception of the universe.

Its construction took almost 20 years, with groups of scientists from all over the world, including Bulgaria, gathered at CERN - the European Organization for Nuclear Research. Among the 6500 scientists forming the international team that designed and constructed the LHC were about 100 from Bulgaria. Scientists from the Bulgarian Academy of Science and Sofia University worked on some of the most important parts of the accelerator - its detectors. The Bulgarian contribution to the project is associated with one of the most crucial in the search for the Higgs boson "God particle", the CMS (Compact Muon Solenoid). And at a diameter of 15m and length of 21m, it's big.

The CMS is made from special crystals that act as subatomic motion detectors - when a tiny particle passes through them, they generate a fine flash of light that is then converted into an electric signal. Each of the 80 000 crystals is individually wired so that scientists can graphically explore what happens inside.

Team leader Leander Litov, head of the nuclear physics department at Sofia University, and Venelin Kozhouharov, 2008 FameLab Bulgaria, a British Council-hosted science communications competition and the only such event on the Balkans, are among the Bulgarians who worked on the CMS detector.

As the time for the first tests and experiments at the LHC approached, an increasing number of voices, including in the scientific community, were raised against the experiments. This led us to ask: Should we be afraid of the LHC? What is its purpose and how it is going to answer our questions?

The basics behind the LHC are simple to explain and do not differ much from other particle accelerators. The particle accelerator, also called an atom smasher, is a long tube in which magnets direct and accelerate tiny particles to very high speeds. And when the required energy is achieved, those particles are collided inside a special piece of equipment, called a detector. Scientist use this data to make conclusions about the structure of the examined particles. The particle accelerator is the most important tool in the modern particle physics toolbox and there are a number of such devices built in laboratories around the world. CERN's is now the largest.

What is impressive about the LHC, in addition to its sheer size and power, is its component parts. The accelerator itself consists of a 27km-long circular tunnel, built 100m underground, in which are installed the lines and equipment needed for experiments. What the LHC will do is accelerate protons, one of the two main components of the atomic nuclei, into two beams that circulate the accelerator until they nearly attain light speed. At this point, each of the protons travels through the entire 27km line 11 000 times a second.

One of the most powerful superconductor magnets helps focus and confine the two beams. The entire installation has liquid helium (-271 degrees Celsius) circulating inside for cooling purposes. Then the two beams are collided inside one of the four detectors built around the line, which can distinguish and plot the trajectories of the particles released from the collision.

What will happen from there is a mystery for now. Some suggest that this will generate an Earth-destroying black hole, though that is clearly not the goal of the project. Instead, scientists want to simulate the conditions of the Big Bang - the point at which our universe was thought to be created. When this is done, the detectors will provide scientists with data that can answer important questions about the nature of the universe. And one of the answers they are eager to get is: does the Higgs boson exist?

The Higgs boson is a theoretical, at this point, particle responsible for the transition between energy and matter. It is so important for our modern perception of the universe that it has even been christened with a divine nickname - the God particle. If the experiments at the LHC prove its existence, it would be the first experimental evidence ever and scientists would know how the energy from the Big Bang formed matter, and us. So, basically, LHC is The Machine that will give us the answer to the life, the universe and everything else, and one can hope that it is not 42 this time.

Actually what happened on September 10 did not involve any kind of particle collisions. It was just a test to generate the first proton beams inside of the LHC. Other tests like this will be conducted on October 21, after which the date of the first collision test is expected to be announced.