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| SCIENCE & TECHNOLOGY | Thursday, September 25, 2003, Chandigarh, India |
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Plasma: the fourth state of matter UNDERSTANDING THE UNIVERSE
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Plasma: the fourth state of matter CAN you guess what the physical state of our universe is? Is it a composition of solid, liquid or gas and in what proportion do these states of matter exist in universe? To our sheer wonder, the whole universe is having only less than one per cent of its total contents in the states of solid, liquid and gas. The rest i.e., the major share of more than 99 per cent is in a state which is entirely different from these three well-known states. This is the fourth state of matter called PLASMA. If Plasma comprises more than 99 per cent of the universe then why do we often remain unaware of it or why does it not figure in the high school syllabus to that extent? The reason is that the fourth and the most abundant state involves a lot of physics and requires rather thorough understanding of quite a few physical phenomena. Interestingly, on our earth this state is well outclassed by its other three counterparts. Still, we can have a flavour of this mighty entity in a lot of things of our common use. Plasma is the main ingredient of the candle flame, tubelight, the ionosphere etc. These days people are even talking about plasma TV and airconditioners. Thus plasma is ready to invade our drawingroom shortly. Now it is time to encounter the confusing question about the composition of plasma. In a very simplified explanation plasma may be stated as a uniform composition of positive and negative charges such that the overall charge of the plasma mass remains neutral. Plasma is formed by ionising or knocking out electrons from neutral atoms. Thus, the electrons having negative charge and the electron deficient ions having positive charge, constitute the neutral lump of plasma. The initial neutral gas mass may be partially or fully ionised resulting in partially or fully ionised plasma. The highly or fully ionised plasma being extremely difficult to confine, is rare on earth, but the partially ionised plasma is rather commonplace as in our tubelight. Then how does the plasma, being so unstable, comprise the lion’s share of our universe? That is because of the gravitational force that counterbalances the instability and on our terrestrial laboratories this force is not strong enough to confine the highly ionised plasma. Plasma has a lot of industrial uses and nowadays it is being used frequently to sort out some age-old complications. We have been facing the deadliest consequences of the ever-increasing medical wastes. But of late by the pyrolysis process these wastes are being transformed into safe end products thus reducing the health hazards considerably. Further, this process may serve as an energy source provided the amount of waste is above a certain quantity. The plastics, which are matter of deep concern today due to their non bio-degradability, are now decomposed safely with plasma. The strength of materials may be increased up to an appreciable extent by implanting nitrogen in their surface. This process is called Plasma Nitriding. An extensive use of plasma is being explored these days to make life better and to make our earth a better place to live in. Given today’s rate of our energy consumption and considering its ever-increasing use, it’s quite obvious that we will run out of our conventional energy sources in a few decades from now. The best known alternatives viz the nuclear fission and solar sources, are in no position to meet this huge demand of energy in the absence of the conventional sources. Further, the waste management in the nuclear fission technique is a tough task and some time or the other it is going to show its ugly face. So, we have to device a suitable alternative before exhausting the conventional sources. For that, it seems that the fusion technique stands as the only safe and reliable alternative. To achieve nuclear fusion on earth, which is a rather routine phenomenon in the stars, we require sustained plasma. Thus the advancement is plasma technology is ultimately targeted to achieve a fusion reactor, which can supply energy at a stretch. Considering the enormous importance of the enhancement of the plasma technology, the developed countries viz. USA, Russia, Japan, China, France, Germany etc have taken it up as a matter of utmost preference. India despite being financially way behind the developed nations, is seriously into the plasma business for about two decades now. The first Indian TOKAMAK (Plasma device), Aditya, came into being in the late eighties at the Institute for Plasma Research (IPR), Gandhinagar, a unit of the Department of Atomic Energy. Further, India’s first Steady State Superconducting TOKAMAK (SST-I) is being commissioned at IPR as a step towards its indigenous fusion reactor, which is expected to come up in a few decades from now. The writer is with the Institute for Plasma Research, Dept. of Atomic Energy, Gandhinagar |
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UNDERSTANDING THE UNIVERSE If all the remote control units of TV sets use infrared signals, why is one remote control unable to manage all TV sets? I do not know the exact difference in the frequency and strength of the signal used by the remote systems of various manufacturers. I am sure variations are possible and they are utilised. In addition there could also be a code. That such codes are used is obvious from the fact that you can do so many things with a remote of any set. You do not use only a simple on-off operation while using a remote. Some standardising might be useful, but then how would the manufacturers set their stamp on the product? I am told though that these days you can buy universal remotes on which you have to enter particulars of the TV set before using it. Incidentally, remotes for some of the sets use microwave rather than infrared transmission. You have perhaps seen the remote used by many car owners to make their cars beep in the parking lot. They can also use them for unlocking the car doors. Clearly this also requires some sort of coded microwave transmission. How are harmful rays produced from the sun during solar eclipse? Your assertion is wrong. The sun does not produce any special rays during an eclipse. It is not even aware that a tiny little round ball called the moon going around a small planet like the earth is coming in the way of its light going to some parts of that planet. Even if it did know it would not care. It is true on the other hand that some people hurt their eyes badly while watching a total solar eclipse. The reason for that is the following. Sunlight during the middle of the day is too strong for eyes. If the pupil of the eye is fully open and we stare at the sun the heat can burn our retina. Ordinarily we never stare at the sun. The discomfort makes us turn our eyes away. In any case we automatically close the pupil of our eyes whenever the light is too bright. However while watching the solar eclipse we go through a phase when the sun is completely covered by the moon and we only see the beautiful corona around the sun. The corona is many orders of magnitude fainter than the disc of the sun and the iris of our eyes is therefore fully open. Then, all of sudden, the moon moves of a little and we see the extremely bright edge of the sun. The flood of light and heat coming through the fully opened apertures of our eyes can cause a serious damage. We do not turn away as quickly as we should because of tremendously heightened interest of the magnificent happening. Therefore we should never watch a solar eclipse with naked eyes. We should use special filters or better still see a projection on a wall using a pinhole camera or another device. I have heard about hot water streams. How are they formed in nature? You know that it is very hot inside the earth. You also know about volcanoes. When a volcano erupts hot lava spits out of the ground and molten rock flows down like a blazing river. This definitely indicates existence of intense heat inside the earth. This happens only in some areas that are said to be volcanic or tectonically active. In these neighbourhoods rock is hot even at levels not so deep in the earth. If water soaking into the earth at a higher level passes near such rocks it is natural that it would be heated; even steam can emerge from cracks in the ground. Such water emerging from a spring at a lower level would produce a hot water stream.  |
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New products & discoveries Robo-snake spy that refuses to die The research and development on “snakebot” project, which is in advanced stages, is funded by aerospace company BAE Systems and is aimed at designing a low-cost robot-spy that can be dropped from helicopter to carry out reconnaisance missions, says a frontline science magazine — New Scientist. The fascinating feature of this robo-spy is its ability to “heal” itself when any of its “muscles” gets damaged, says Computer scientist Peter Bontley of University College, London, who, along with his colleague Siavash Haroun Mahdavi, is working on the project. —
PTI Energy from bugs Damnation... your mobile phone, on which your work and social life depend, has become a useless lump of plastic and silicon: the battery is dead. No problem. Just reach for the nearest bowl of sugar, flip open the phone, top up the battery with a wee spoonful, give it a little time — and hey presto, you are connected to the world again. The sci-fi scenario may lie in the not-too-distant future, thanks to a pair of US-based scientists who say they have invented the world’s first efficient “bacterial battery.” In a Pentagon-backed project, University of Massachusetts researchers Swades Chaudhuri, an Indian, and Derek Lovley, an American, say the battery’s source is an underground bacterium that gobbles up sugar and converts its energy into electricity. —
AFP Sponge has
fiber optic cables Fiber optic cables — an amazing invention showing how clever prople can be, right? Maybe so, but nature got there first, US researchers have reported. A deep-sea sponge with a “skeleton” made out of silica did it first and did it better, the researchers said. It has spicules — skeletal structures — that look very much like modern fiber optic cables, except they don’t crack, the team at Bell Laboratories/Lucent Technologies in Murray Hill, New Jersey, reported. Studying it could help scientists figure out better ways to make fiber-optic cables and networks, the researchers suggested — Reuters Heart built with cow tissue In a first-of-its-kind operation for curing tumours, surgeons reconstructed upper chambers of a woman’s heart with cow and human tissue after removing it out and then placed it back. With this successful operation, the patients of heart tumours can now hope to avoid undergoing risky heart transplants, said Bartley Griffith, one of the doctors who carried out the surgery claimed. The 12-hour operation was performed last month at the University of Maryland Medical Center in Baltimore on a 46-year-old Massachusetts woman who has been battling a rare, recurring and life-threatening heart tumour, called myxoma. —
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WITH PROF YASH PAL
In what may redically alter the existing contours of military reconnaisance and battle-field spying and help curtail casualties in spying missions, a British defence lab is developing a snake-like spy robot or “snakebot” that keeps on slithering even if it gets partly damaged.