Five facts about 'Big Bang' lab

The European Organisation for Nuclear Research, known as CERN, on Wednesday began an experiment to recreate conditions akin to Big Bang, which scientists believe gave birth to the universe.

Its Large Hadron Collider (LHC) will seek to collide two beams of particles at nearly the speed of light in a series of experiments spread over next six weeks. Scientists will circulate a beam in one direction around the accelerator, then the other, later sending beams both ways to cause collisions. Following are some facts about the Big Bang and CERN's particle-smashing experiment which is also set to be the biggest data crunching exercise ever undertaken by mankind.

The final tests involved pumping a single bunch of energy particles from the project's accelerator into the 27-km (17-mile) beam pipe of the collider and steering them counter-clockwise around it for about 3 km (2 miles).

The collider aims to simulate conditions milliseconds after the "Big Bang" which created the universe around 13.7 billion years ago. The collisions, in which both particle clusters will be travelling at the speed of light, will be monitored on computers at CERN and laboratories around the world by scientists looking for, among other things, a particle that made life possible.

The elusive particle, which has been dubbed the "Higgs Boson" after Scottish physicist Peter Higgs who first postulated nearly 50 years ago that it must exist, is thought to be the mysterious factor that holds matter together.

Recreating a "Big Bang," which most scientists believe is the only explanation of an expanding universe, ought to show how stars and planets came together out of the primeval chaos that followed, the CERN team believes.

Its essential feature is the emergence of the universe from a tiny speck about the size of a coin but in a state of extremely high temperature and density. The name "Big Bang" was coined in 1949 by British scientist Fred Hoyle to disparage a then emerging theory about origins that countered his own "steady state" view: that the universe had always existed and was evolving but not expanding.

According to the Big Bang model, the universe expanded rapidly from a highly compressed primordial state, which resulted in a significant decrease in density and temperature. Soon afterward, the dominance of matter over antimatter (as observed today) may have been established by processes that also predict proton decay. During this stage many types of elementary particles may have been present. After a few seconds, the universe cooled enough to allow the formation of certain nuclei.

The theory predicts that definite amounts of hydrogen, helium, and lithium were produced. Their abundances agree with what is observed today. About 1,000,000 years later the universe was sufficiently cool for atoms to form.

When two beams of protons collide, they will generate temperatures more than 100,000 times hotter than the heart of the Sun, concentrated within a miniscule space. Meanwhile, the cooling system that circulates superfluid helium around the LHC's accelerator ring keeps the machine at minus 271.3 degrees Celsius (minus 456.34 degrees Fahrenheit).

Smaller colliders have been used for decades to study the makeup of the atom. Less than 100 years ago scientists thought protons and neutrons were the smallest components of an atom's nucleus, but in stages since then experiments have shown they were made of still smaller quarks and gluons and that there were other forces and particles.

To collect data of up to 600 million proton collisions per second, physicists and scientists have built devices to measure the passage time of a particle to a few billionths of a second. The trigger system also registers the location of particles to millionths of a meter.

The data recorded by the LHC's big experiments will fill around 100,000 dual-layer DVDs each year. Tens of thousands of computers around the world have been harnessed in a computing network called "The Grid" that will hold the information.
CERN, the European Organisation for Nuclear Research, is one of the world's largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works.

Founded in 1954, the CERN Laboratory sits astride the Franco-Swiss border near Geneva. It was one of Europe's first joint ventures and now has 20 member states, plus 6 actively participant observers including the United States and Russia.