A step closer to grand unified theory
S.S. Verma

Understanding the physical universe and its working has been the top priority with the scientists for which the highest importance goes to the building blocks of matter/antimatter and forces of interaction between them.

Particles like protons and neutrons making the atomic nucleus are no more considered as elementary particles. Quarks and Leptons are the building blocks which build up matter, i.e., they are seen as the elementary particles.

In the present standard model, there are six "flavours" of quark as i) Up and Down Quarks: these are the most common and least massive quarks, being the constituents of protons and neutrons ii) The Strange Quark: the lambda is a baryon which is made up of three quarks: an up, a down and a strange quark iii) The Charm Quark iv) The Top Quark and The Bottom Quark. They can successfully account for all known mesons and baryons (over 200).

The name "quark" was coined by Murray Gell-Mann who received the 1969 Nobel Prize for his work in classifying elementary particles. Since then various discoveries related to elementary particles have bagged many Physics Nobel prizes. Last year’s (2003) Physics Nobel prize was also given for the experimental verification of "cosmic neutrino". Continuing the same, this year (2004) Nobel Prize in physics is awarded to three Americans — David J Gross (Univ. of California), H David Politzer (CALTECH) and Frank Wilczeck (MIT) for their work in the discovery and exploration of strong force and quarks. According to Nobel foundation "the research helped physics get one step closer to the development of the grand unified theory".

Four elementary types of forces acting among particles are: strong, weak, electromagnetic and gravitational force. Each force has its own characteristic bosons: gluons mediates between quarks through strong force/colour force; photon carries the electromagnetic force; the W and Z bosons represent the weak force and graviton (hypothetical boson) is expected to represent gravitational force. Physicists call the theoretical framework that describes the interactions between elementary building blocks (quarks and leptons) and the force carriers (bosons) the Standard Model. Gravity is not yet part of this framework, and a central question of 21st century particle physics is the search for a quantum formulation of gravity.

Though still called a model, the Standard Model is a fundamental and well-tested physics theory. Physicists use it to explain and calculate a vast variety of particle interactions and quantum phenomena. High-precision experiments have repeatedly verified subtle effects predicted by the Standard Model.

So far, the biggest success of the Standard Model is the unification of the electromagnetic and the weak forces into the so-called electroweak force. Physicists think it is possible to describe all forces with a Grand Unified Theory. One essential ingredient of the Standard Model, however, still eludes experimental verification: the Higgs field.

Colour is the strong interaction analog to charge in the electromagnetic force. The term "colour" was introduced to label a property of the quarks which allowed apparently identical quarks to reside in the same particle. To allow three particles to coexist and satisfy the Pauli exclusion principle, a property with three values was needed. The idea of three primary colours like red, green, and blue making white light was attractive, and language about "colourless" particles sprang up.

It has nothing whatever to do with real colour, but provides three distinct quantum states. The property can be considered something like a "colour charge" with three distinct values, with only colour neutral particles allowed. The antiquarks have anti-colours, so the mesons can be colourless by having a red and an "anti-red" quark.

The idea of colour is supported by the fact that all commonly observed particles have either three quarks (baryons) or two (mesons), the combinations which can be "colourless" or "colour neutral" with the three values of colour.

The strong force between quarks is called the "colour force" and is one of the fundamental forces explained greatly by the Nobel Laureates of this year. It is so strong that it is impossible to have a colour charged particle alone. Therefore, freestanding particles are always colour neutral. The gluon, the carrier particle of the colour force, and quarks are the only colour charged particles. Since quarks make up the baryons, the colour force is the source of the strong interaction which extends beyond the proton or neutron to bind them together in a nucleus. The colour force does not drop off with distance and varies from minimum at short distances (so that the quarks are like free particles within the confining boundary) to maximum when they (quarks) begin to get too far apart.

Although understanding of quark model has gained a lot of ground theoretically as well as experimentally to believe that there are no more sets of quarks and leptons but theorists speculate that there may be other types of building blocks, which may partly account for the dark matter implied by astrophysical observations.

The writer is from the Dept. of Physics, SHSL-CIET, Longowal

ET should have written

Writing, rather than phoning, is probably the best way to contact extraterrestrials, American scientists have said.

So instead of phoning home, it could have been more energy-efficient if ET had inscribed information and physically sent it, because radio waves disperse as they travel.

"Think of a flashlight beam," said Prof Christopher Rose, of Rutgers University in New Jersey who reported his finding in the science journal Nature.

"Its intensity decreases as it gets farther from its source. The same is true of the beam of a laser pointer, though the distance is much longer," he added in a statement yesterday.

Rose and his colleague, physicist Gregory Wright, were pondering how to get the most bits per second over a wireless channel when they concluded that the detectability of a signal diminishes with distance.

If the recipient isn’t listening or misses it, the message may have to be sent numerous times but a physical message encoded in an object lands somewhere and stays there. Messages from aliens could possibly be embedded in organic material in an asteroid, for example.

"If haste is unimportant, sending messages inscribed in some material can be strikingly more efficient than communicating by electronic waves," said Rose.  — Reuters

Cool your product from 22`BA C to 2`BA C in just two minutes with no electricity, simply by 100% natural evaporation, using an advanced simulation technique from Europe’s Ariane launcher.

"We have managed to develop a controlled fast cooling system, without the use of outside energy, where the temperature drops 70 times faster than in a standard refrigerator," says Fadi Khairallah, founder of Thermagen, the company behind this innovation.

"By using vacuum evaporation our process absorbs the heat energy of the product, thereby cooling it at high speed whenever required. To determine the control of the vacuum water evaporation process we used a simulation technique from the space industry." The same advanced simulation code is used to simulate the operation of the Ariane rocket engines.

The slow and nearly constant vibrations of earth’s crust stem from severe winter weather over some of the world’s oceans, a new analysis of seismic data suggests.

Our planet’s outer shell is constantly pulsing. Earthquakes trigger many of these ripples, but the ground undulates imperceptibly even on days devoid of significant temblors.

Scientists have dubbed these persistent vibrations "Earth’s hum." The largest undulations in this seismic background noise occur at frequencies between 2 and 7 millihertz, or once every few minutes, says Barbara A. Romanowicz, a seismologist at the University of California, Berkeley.

Scientists working at the US Commerce Department’s National Institute of Standards and Technology (NIST) have demonstrated the design of a new minuscule atomic clock that could be used for precise timekeeping in portable, battery-powered devices for secure wireless communications and more precise navigation.

The device is 100 times smaller than any other atomic clock. Its inner workings are about the size of a grain of rice and it consumes less than 75 thousands of a watt, allowing it to run on batteries, a NIST release said. As atomic clocks get smaller and cheaper and use less power, they could replace quartz crystal oscillators in many common products such as computers, offering better time keeping by several orders of magnitude, NIST added. — PTI

Scientists in Japan have developed a "crystal-shaped" sponge that could help reduce vehicular emissions by trapping pollutants before the catalytic converter is ready for the job.

A team of researchers, led by Tatsuya Okubo, at the University of Tokyo found zeolite, a crystal made from silicon, aluminium and oxygen, to be promising as a hydrocarbun trap, a report published in ‘Nature’ said. Up to 80 per cent of hydrocarbons released into the atmosphere are emitted from vehicles before the catalytic converter reaches its operating temperature. — PTI

You have put me a difficult question. That is strange because you are asking about something in which millions rest their belief. I cannot scientifically prove or disprove His existence. I know that it is a concept that is widely accepted. That no one can deny. But you could also say that God is a necessity of humans. They look for reasons for their existence, order and natural law. A God ends this search. He is no less important even if He is a human creation. He is not believed to be a physical being that can be detected through physical means of science. One can of course say that mere existence of the universe with its order and the immutable working of the natural law is evidence enough. Why should any one ask for more? But then one has also to accept that once the natural laws are in place, there is not very much left for God to do? He cannot be expected to break His own laws, no matter what the circumstances. On the other hand the prayers of the believers might have a beneficial effect. Perhaps the reason for this is not because the Supreme Being really listens to every request or indulges in nepotism.

The reason might be that the act of prayer and meditation is intrinsically good for those of us who pray - it submerges feelings of self-importance and breeds a welcome humility. That might also explain the deep humanity of many truly religious persons. I am personally so grateful that I was given a chance to live in this magnificent universe, with so much creativity, so much beauty and such amazing working together of various laws. The understanding of some of these laws gives me humility and joy that I was also constructed to develop a faculty of comprehension. I have no quarrel with different ways of acquiring this humility and feelings of gratefulness. I do, on the other hand, highly deplore the animosities that have plagued our country and the world merely on the basis of the difference in labels and brand names we have given to these different ways.

This is a question to which I am not able to give a detailed answer. I am not sure any one knows it fully. But a difference can be easily demarcated. When we are asleep our brain is given rest but only part of its functions are given a holiday. It is still on guard duty should a major need arise. Our pain and temperature sensing circuits are not shut down. If we are cold we snuggle deeper into the blanket. If we are warm we throw off the covers. Metabolism goes on. The food is digested. The memories and images are still stored in the brain but the manner in which they connect up and serialise is not under conscious control. This is the reason psychologists believe that analysis of dreams when the control of the conscious is weakened is a good way to understand the normally suppressed subconscious. However, when we are unconscious the control of senses is almost completely stopped. We still metabolise and breath, but we cannot be woken up by a loud noise, a pinch or sprinkling of water on our face. Perhaps we do not dream either. There is a major circuit block in the brain. Unconsciousness follows a major trauma or metabolic malfunction. I feel that this is also designed to protect us from extreme pain and discomfort.