In the beginning, there was a big bang. A little while later, matter expanded in all directions. That led to the familiar universe, with the familiar physical laws that generations of scientists have decoded through logic and experimental observation. But we don’t know what the physical laws and conditions were at the very instant of the big bang. Particle physicists have made many educated guesses about conditions at that point of time and how those could give rise to the universe. CERN’s Large Hadron Collider commissioned last Wednesday is the first artefact that actually comes near reproducing the conditions at the instant of creation. Thus for the first time, humanity has a chance to experimentally verify those guesses.
The $4-billion LHC is housed in a circular tunnel running both sides of the Swiss-French border. The tunnel is 27 km in circumference and only 3.8 metres in width. It is lined with over 9,000 massive (32 tonnes) magnets, all cooled to -271 degree centigrades. It contains two vacuumed pipes that run parallel to each other and these pipes are joined at four points in “collision chambers”. The environment is emptier and colder than interstellar space. It is the largest and the most expensive machine ever built. The task of the LHC is to charge fundamental particles with huge amounts of energy and blast them through the two pipes simultaneously in clockwise and counter-clockwise directions. The magnets will keep the particles on their ordained courses and ensure collisions occur at the four intersections. The particles will be moving at speeds very close to that of light, whizzing 11,000 times a second through the 27-km ring. When they slam into each other at such speeds, their interactions should create conditions very similar to the instant of post-big-bang.
The LHC has been commissioned without glitches and beams have been pushed through (one at a time) in both directions. Once the collision experiments start on October 21, the vast amounts of data generated will be made available to scientists from around the world. In fact, the massively parallel computing required to analyse that data has in itself led to advances on the information technology front. About 2,000 scientists are direct participants in this experiment. The Indian scientific establishment has contributed its mite, by designing, for example, the magnetic array and some of the controller chips.
The most widely accepted of all theories is called the Standard Model. This predicts the presence and characteristics of certain particles. All but one of these has already been directly observed and experimentally verified to closely coincide with predictions. The one particle predicted by the Standard Model that has not been observed so far is the so-called “god particle” or Higgs Boson, which is believed to be responsible for imparting the quality of mass. If Higgs Boson is found, it will be strong evidence that the Standard Model is right. That brings physics one key step closer to the holy grail of a grand unified theory that shows electromagnetism, and the strong nuclear and weak nuclear forces are all actually different manifestations of the same unified force. If on the other hand, Higgs Boson is not found, the Model will need re-examination because it is wrong in some aspect. Either way, mankind’s understanding of creation will grow as Stephen Hawking (who has a $100 bet that Higgs Boson will not be found) has pointed out.
The commissioning of LHC has stirred public imagination in remarkable ways. A rap song released by light-hearted CERN personnel has become a global hit on YouTube. There has been panicky speculation that the world could come to an end and at least one tragic suicide has been triggered by such fears. The end of the world is exceedingly unlikely. More likely, there will be several Nobel prizes handed out once scientists start making sense of the data.
