My intention was to write an article about fascinating subjects and noble ideas that come pell-mell, each with its appropriate imagery and I had before me ink and pen and several sheets of virgin paper. But just when I was about to hold my pen, a sudden thought flashed across my mind. What constitutes me and half a dozen inanimate objects in my room? This perennial question is perhaps the most challenging one before human mind.       

Man has always been in search of the origin of the innumerable entities surrounding him. Who knows how far, and how deep he can reach in this search. Can we ever discover the smallest particle? If it is possible, what would be it like; its size, its mass, and its interaction with other particles? Is it indivisible? How can its discovery change our view of life? These are indeed very strange questions. It feels as if there are trillions of versions of us in us.

Until 1932, physicists viewed the proton, neutron and the electron as elementary because with the exception of the free neutron, they're all very stable. This theory soon fell apart and beginning in 1937 many new particles were discovered in experiments involving high energy collisions between known particles. These new particles are characteristically unstable and have very short half lives, ranging between 10-6 to 10-23 sec. So far more than 300 of them have been discovered. Physicists were bewildered by the large number and variety of subatomic particles being discovered. They wondered if the particles were like animals in a zoo or if a pattern was emerging that would provide a better understanding of the elaborate structure in the sub nuclear world. In the last thirty years, physicists have made tremendous advances in our knowledge of the structure of matter by recognizing that all particles (with the exception of electrons and few others) are made of smaller particles called quarks. Thus protons and neutrons, for example, are not truly elementary but are systems of tightly bound quarks.

All the particles, other than photons can be divided into two broad categories, hadrons and leptons according to their interactions. Particles that interact through strong force are called hadrons. There are two classes of hadrons viz. mesons and baryons, distinguished from their masses and spins. All mesons are known to decay finally into electrons, positrons, neutrinos and photons. The pion is the lightest of all mesons with a mass of about 140 MeV/c2 and a spin of 0. Leptons, on the other hand participate in weak interaction. Although hadrons have size and structure, leptons appear to be truly elemental with no structure. As stated in the beginning, this is a strange world of particles. Many particles discovered in 1950's like K, ∑ etc. were found to exhibit unusual properties in their production and decay and hence are called strange particles. To explain their unusual properties, physicists introduced a law called conservation of strangeness, together with a new quantum number S called strangeness. In 1963, Glenn Mann and George Zwig independently proposed that hadrons have a more elementary substructure. According to their model all hadrons are composite systems of two or three fundamental constituents called quarks. In the original model there were three types of quarks designated by symbols u, d and s. These are given the arbitrary names up, down and sideways (or now more commonly, strange). Although the original quark model was highly successful in classifying particles into families, there were some discrepancies between predictions of the model and certain experimental decay rates. As a consequence, a fourth quark was proposed. It was designated as c and given the property called charm.

"Quarks are slaves of their own charge ……… bound like prisoners of a chain gang …… Any locksmith can break the chain between two prisoners but no locksmith is expert enough to break the gluon chains between quarks. Quarks remain slaves forever."

Now the question that faces me is; what’s inside a quark? Is it matter? Is it energy? Or is it string? Since isolated quarks are experimentally unavailable due to color confinement, the simplest available experiments involve the interactions of, first, leptons with each other, and second, of leptons with nucleons, which are composed of quarks and gluons. To study the collisions of quarks with each other, scientists resort to collisions of nucleons, which at high energy may be usefully considered as essentially 2-body interactions of the quarks and gluons of which they are composed.

Thus elementary particle physicists tend to use machines creating beams of electrons, positrons, protons, and anti-protons, interacting with each other or with the simplest nuclei (e.g, hydrogen or deuterium) at the highest possible energies, generally hundreds of GeV or more. At present the highest energy accelerators are all circular colliders, but it is likely that limits have been reached in respect of compensating for synchrotron radiation losses for electron accelerators, and the next generation will probably be linear accelerators 10 times the current length. An example of such a next generation electron accelerator is the 40 km long International Linear Collider, due to be constructed between 2015-2020.

Considering such an immense intricacy in creation, flanking a human being, few of the complex and intangible qualities are indispensable to be known thoroughly and masterly. It is unfortunate that the basic concepts of life have been ludicrously misinterpreted and misunderstood by most of us. Eventually it results in the infusion of confusion in our minds regarding the purpose of living. Can't we move forward without despising others as cowards and poltroons? It’s time to submit our will to the Almighty and work shoulder to shoulder for the betterment of our society.

( Author is a Research Scholar, Educator and Columnist}