Punjab facing groundwater crisis?
India’s most agriculturally prosperous state, Punjab, is staring at an impending groundwater crisis. Over-extraction of groundwater and faulty cropping practices could affect India’s foodgrain production, writes Richard Mahapatra.

Threat posed by super disasters
by Radhakrishna Rao
BOTH man-made and nature-induced disasters have been causing incalculable lose to human lives and property across the world with recurring regularity. Earthquakes, typhoons, landslides and floods are being reported with an increasing intensity from round the world. No doubt, most of the disasters being natural can hardly be avoided.

Selection of an EPBAX
by Deepak Bagai
The electronic private automatic branch exchange (EPABX) is equipment that has made day-to-day working in the offices much simpler, especially in the area of communication.

Science Quiz
by J. P. Garg

The next-generation space travel
by Sarabjeet Singh

Nuclear rocket engine

Liquid-propellant rocket engine

THE earth is situated fairly deep in the gravity well and it takes a velocity of 11.6 km/sec to jump out. And as we are in the ‘centuries old’ habit of living in a gravitational field of 1 g (9.8m/sec2), therefore, an ideal rocket would be that which provides a continuous acceleration of 1 g (though human body can tolerate acceleration up to 15 g)

This rocket will soon speed up to near the speed of light (too fast... Isn’t it?) plus the occupants will be free from all ill effects of free fall ie nausea, muscular weakness, reduced sense of taste, and leaching of calcium from their bones etc. But have you guessed how far is the nearest star?

If for example, the sun were scaled down to the size of a cherrystone, the earth would be a grain of sand three feet away and... the nearest star would be another cherrystone 140 miles away. Some of you (who are very fond of travelling to every nook and corner and just can’t afford to miss any tourist spot of the world) might feel disappointed and wish if we might had some faster than light spaceship like’ Starship USS Enterprise’ in Star Trek.

Today nearly all developed countries are very serious about their space programmes. Present rocket technology relies on high initial speeds, which gradually decrease, whereas to attain half the speed of light a continuously firing thruster would be needed, which would provide steady acceleration.

Getting our spaceship out beyond the solar system presents certain problems if the spacecraft is to travel at sufficiently high speed to get anywhere... in the lifetime of men who launch it. The first and the biggest problem is the very huge amount of fuel required and of course the weight of fuel... because the fuel itself has to be accelerated with the crew and machines of the rocket. Another problem is that kinetic energy increases according to square of velocity (KE-½mv2), so that to get 10 times the speed 100 times the work is needed. Further more, according to the Einstein’s law of conservation of mass-energy (E-mc2) as the spaceship approaches the speed of light her mass continuously increases so that if she could reach the light speed of 186,000 miles per second, she would have infinite mass and, therefore, infinite momentum. Theoretically, all matter is limited by the speed of light. Einstein has said in his theory of relativity that nothing can travel faster than light.

For long distance space travel there have been many methods, proposed by scientists and science fiction writers but none is yet quiet satisfactory. A few of them are ionic drive, nuclear drive, Ramscoop starship, high pressure propulsion system, photonic spaceship etc.

In ion drive (also called electric drive) ions (charged particles) are accelerated by magnetic fields. Any atom can be ionised by stripping it of electrons. Heavier the atom used, greater is the thrust. Mercury is a conveniently heavy but not very expensive, readily ionised, and is the likeliest propellant.

Nuclear drive could use either nuclear fission or nuclear fusion. Small pellets of thermonuclear propellants deuterium and helium-3 are projected into reaction chamber and bombarded by high energy electron beams. Nuclear fusion results and exploding plasma, very very hot and energetic, is swept out of spaceship.

In other words this is a series of pulsed H-bombs @of 250 per second. The products of reaction are charged and can be controlled, but unfortunately helium-3 is very rate.

Dr. Robert L. Forward of Hughes Research Labs in California has proposed using the pressure of light itself as a propulsion device. An array of laser beams would be built in space close to the sun, and they need not be too powerful and a figure of 35-40 megawatts will suffice.

The lasers would be beamed in unison at a starship which would carry huge, thin, rigid sail of metal. The pressure of the lasers on the sail would accelerate the ship away (but oops... what about brakes?). The ship would swing around target star and be decelerated by the same lasers on the way back.

The next is the interstellar ramjet often called Bussard ram-scoop starship suggested by American physicist Robert Bussard in 1960. The most beautiful and rewarding feature of this system is that it does not carry its fuel with it. The space between the stars is not a perfect vacuum.

There are one or two atoms of hydrogen per cubiccentimetre of space. This starship will have to be first speeded up (from auxiliary power) until high enough where this space ship would be travelling so enormously fast, through such a huge volume of space every second, that this negligible gas density would seem to be dense hydrogen cloud. The invisible funnel shaped scoop would consist of a vast electromagnetic field projected by great superconducting coils. This would ionise the H-atoms and suck them into the fusion-engine. There are many problems with this system and none could be solved with our present knowledge.

Now the most fanciful is the matter-antimatter drive also called photonic drive. This drive is said to propel the famous starship ‘USS Enterprise’ in Star Trek. Ordinary matter has negatively charged electrons around positively charged nuclei; antimatter would have positively charged anti electrons-positrons-and negatively charged nuclei. A particle and its antiparticle can join together in a ‘suicide pace’ since their entire mass gets converted into radiant energy (photons). In a fission bomb only 0.1% of plutonium mass becomes energy. In fusion bomb it is 0.5% In matter-antimatter bomb it is 100%. 1 kg of matter combined with 1 kg of antimatter would release the energy of 43 1-megaton hydrogen bombs!

The principle of the photonic motor is to produce atomic particles and their antiparticles in equal number. The reaction will be made to occur at the focus of the parabolic mirror so that the photons get reflected in one direction. The thrust of photons on the mirror will push the spaceship.Yet every time you switch on a hand torch the light exerts a tiny rocket thrust, although there is no danger of your being yet propelled backwards...

Taking a theoretical photonic-spaceship of 200 tons weight, it is estimated that, of this 150 tons would have to be fuel. In this case it might be possible to reach a speed of 600 million miles an hour after a year of acceleration.

This is near the speed of light. But till date, no known material could be used to handle the fuel (How will we store antimatter? Because, for example on the earth we need an antimatter container of (say) steel to store (say) antiwater. But how to keep this container on (say) a table made of matter?) and some as yet unknown ‘superconductor’ could be employed to make the mirror.

War rockets ‘Arrows of flying fire’ propelled by gunpowder were described by Tsen Kung Liang of China in 1042. On 16 March 1926 Robert H. Goddard launched the first liquid fuelled rocket which reached a height of 41 feet and travelled 184 feet and on 21 July 1969 man was on the moon.

But it will not be before 50 years that any of such hi-tech system would be practically feasible. Till then keep faith in hardworking scientists and engineers.

Punjab facing groundwater crisis?
India’s most agriculturally prosperous state, Punjab, is staring at an impending groundwater crisis. Over-extraction of groundwater and faulty cropping practices could affect India’s foodgrain production, writes Richard Mahapatra.

PUNJAB, which produces 60 per cent of the wheat and 40 per cent of rice of the central pool, is heading towards a groundwater crisis. In the past two decades, the groundwater table in Punjab has been falling at the rate of 25-30 cm a year, says N.S. Pasricha of the soil engineering department, Punjab Agricultural University (PAU), Ludhiana. According to a study by Gurdev Singh Hira, a senior soil physicist at PAU, out of the state’s area of 5.03 million hectares, 4.32 million hectares has a falling water problem. Going by the statistics of the state groundwater department, the area where the water depth has gone below 10 m increased from 3 per cent in 1973 to 25 per cent in 1990 and 46 per cent by 1994. If the water table goes below 15 m, the tubewells will stop functioning.

The State of the World Report, 1998, published by the Washington-based Worldwatch Institute, says the gap between water use and sustainable yield of the aquifer is so high that the aquifer under Punjab could be depleted by the year 2025. “In almost half of Punjab, the depletion of water resources is leading to a crisis,” says K K Mehta, regional director of the Central Ground Water Board, Chandigarh.

The primary reason for extraction of groundwater is for agricultural purposes, particularly for water-intensive crops such as wheat and rice. About 60 to 70 per cent of the total cultivated land in Punjab is under wheat-rice cultivation. In 1960, just before the Green Revolution, the area under tubewell irrigation was 22 per cent. This had increased to 57 per cent in 1996.

After the Green Revolution, farmers in Punjab abandoned their traditional cropping practice in favour of the government-supported wheat-rice cropping method. As a result, the shallow wells, traditionally used for irrigation, have run dry. While affluent farmers have started using deep tubewells for irrigation, the not so lucky have shifted to sugarcane cultivation, where the requirement for water is not so high.

Low yield and high costs may force many farmers to abandon agriculture. “The productivity of the system is no longer sustainable for farm holdings less than 5.67 ha”, says Inderjit Singh Jiyajee, convener of the Movement Against Social Repression, Chandigarh, which has been spearheading a movement to protect the farmers from the declining growth. “This is the political leadership’s failure as they have not formulated a proper water management policy,” Jiyajee adds.

Chief Minister Prakash Singh Badal, however, does not think the groundwater crisis could jeopardise the nation’s food security given that it contributes the maximum to the central pool. Besides, agriculture contributes 44 per cent to the state’s gross domestic product. According to him the present policy of fertiliser subsidy and free electricity to farmers is “practical and suitable to the Indian socio-economic condition”. Experts, however, say these factors are responsible for the present crisis.

“The problem is not as acute as is being projected. It is a theoretical evaluation and there is no truth in it,” says Badal. What he seemingly ignores is his government departments’ admission of the problem. Over the last three years, high level officials of the agriculture and groundwater departments have met for five times to deliberate on the groundwater crisis. “I do get this complains but don’t find any logic behind this. If water is that scarce then how come the productivity is going up every year,” says the Chief Secretary, who convened a meeting in January this year to discuss groundwater depletion in central Punjab and water-logging in the state’s south-west areas.

While the situation is serious, its solution — a major shift from the rice cultivation to a less water intensive non-cereal crop — seems unacceptable to the farmers. Wheat-rice cultivation is lucrative because the government supports it through massive procurement programmes, while there are none for traditional non-cereal crops.

“The crisis is because of a faulty farming practice caused by a faulty long-term planning. No non-cereal crops are grown between cereals which consume less water,” says Pasricha. Traditionally, the cropping pattern in Punjab was a cycle of two years farming followed by one year of fallow period. “This retained the soil fertility and also lowered pressure on water extraction,” says Jiyajee.

It is feared that if the present rate of utilisation of underground water continues, the existing centrifugal pumping system will become non-functional in the future. Water than may have to be drawn from deeper layers, wherever possible, by submersible pumps. Unless drastic steps are taken by the state government, the people of Punjab will have to live with an unpleasant reality: little groundwater and even little foodgrain production. — CSE

Threat posed by super disasters
by Radhakrishna Rao

BOTH man-made and nature-induced disasters have been causing incalculable lose to human lives and property across the world with recurring regularity. Earthquakes, typhoons, landslides and floods are being reported with an increasing intensity from round the world. No doubt, most of the disasters being natural can hardly be avoided. But then the extent and intensity of these disasters have been accentuated by human action, including deforestation, pollution and excessive strain on natural resources. No wonder, environmentalists have warned that climate change, deforestation and over population over the next 10 years could lead to a “decade of super disasters.”

For instance, a joint research study by the International Federation of Red Cross and Red Crescent says, “everyone is aware of the environmental problems of global warming and deforestation on the one hand and the social problems of increasing poverty and growing shanty towns on the other. When these two factors collide you have a new scale of catastrophe” .

As it is, the natural disasters that took place during 1998 created more ‘Environmental refugees” than the wars and ethnic conflicts put together. For instance, the hurricane Mitch which caused widespread havocs in Central America left 10,000 people dead and 2.5-million temporarily dependent on aid. “The explosive combination of human driven climate changes and rapidly changing socio-economic conditions will set off chain reaction of devastation leading to super disasters”, the report says and adds “and the world is at risk as never before. Climate change will be manifested in a catalogue of disaster such as storms, droughts and floods unparalleled in modern times. The main uncertainty is where and when they will occur.”

It has now been revealed that the ongoing process of global warming could melt the 15,000 glaciers in the Himalayas in 40 years if the current rate of the shrinking of the “largest body of ice” outside the polar caps continues. For instance, the Gangotri glacier has lost one-thirds of its 15 miles stretch in the last 50 years. The result of such shrinking means a vastly reduced water supply to the plains of northern India. Similarly, the Alpine ranges in Switzerland have lost 50 per cent of the glaciers over the last two decades. At a recent seminar on global warming held at Southampton University in Great Britain,it was said that the melting of the snow and ice could raise the sea levels leading to the inundation of low lying islands and even certain coastal areas of several countries.

Selection of an EPBAX
by Deepak Bagai

The electronic private automatic branch exchange (EPABX) is equipment that has made day-to-day working in the offices much simpler, especially in the area of communication.

The EPABX may be defined as a switching system that makes available both internal and external stitching functions of any organisation.

The selection of an EPBAX is a difficult task and requires deep knowledge of traffic pattern of the office. By using an EPABX both the internal and external needs of the organisation are fully served. With the advent of powerful microprocessors and advancements in the field of computers, the EPBAX can boast of versatile features. Hotline can be established between the boss and his immediate subordinates.

The feature of a call transferring and forwarding is another area enabling mobility of the users. Autoconferencing and automatic redialling of numbers found engaged on the first trial are some of other advancements in the features of the EPBAX.

The selection of an EPBAX for an organisation should be preceded by a thorough study of the needs of the office. The exchange should be supporting features like voice DISA-n-auto attendant. This feature helps in doing away with a receptionist or an attendant. Further, the specifications should ensure inbuilt paging, auto fax homing, hot outward dialing, remote dialing, remote servicing and auto shut dynamic lock.

Science Quiz
by J. P. Garg

1. Name the American chemist who was awarded the 1954 Nobel Prize in chemistry for his work on chemical bonds and the structure of molecules, and the 1962 Nobel Peace Prize for his efforts towards nuclear disarmament.

2. Indian soldiers will soon be equipped with indigenously developed but highly advanced helmet — mounted electronic devices for soldier-to-soldier and unit-to-unit communication on the battlefield. Can you name these devices?

3. A large number of people in rural areas of West Bengal and Bangladesh are suffering from various skin ailments and even dying due to the consumption of contaminated water taken out from wells. What is this contamination due to?

4. This bomb is made from napthalate and palmitate compounds in gelatinous petroleum. On hitting its target, it spreads out, clings to and burns everything it falls upon. Which bomb are we talking about?

5. Fireworks ignited on Divali display beautiful colours, which are characteristic of the elements the compounds of which are mixed with the combustible material. Name the elements the compounds of which respectively produce white, red, yellow, green and blue colours.

6. Can you think of a “miniature solar system” that is the building block of all matter?

7. Living organisms use two forms of energy to meet their organic requirements. What are these two types of energy?

8. A microwave oven is used to heat food by means of very short wavelength waves called microwaves. Name the instrument that generates these waves in the oven. Which basic process takes place inside the food item that causes instant heating?

9. ‘Apus’, ‘Cetus’ and ‘Ursa Major’ are the Latin names of three recognised constellations (groups of stars). Can you tell their English names?

10. The science fiction book “The Invisible Man” narrates the story of a young chemist who succeeds in making himself invisible but cannot find a way to make himself visible. Name the author of this book.

Answers

1. Linus Carl Pauling 2. Millimetre-wave radios 3. Highly poisonous metallic element arsenic 4. Napalm bomb 5. Magnesium, strontium, sodium, barium and copper 6. Atom 7. Light and chemical energy 8. Magnetron; Microwaves produce rapid vibrations in molecules of water contained in food and the resulting increase in kinetic energy causes heating 9. “The Bird of Paradise”, “The Whale” and “The Great Bear” 10. H.G. Wells.

Childnet International Award
Cable and Wireless India has announced the launch of the Childnet International 2000 Award, which rewards children (and those working with them) who are developing outstanding Internet projects which benefits children.

For the 2000 awards there are four separate categories for individuals, school, non-profit organisation and government funded strategic initiatives.

The award judges are particularly keen to reward innovative initiatives which have been developed on limited resources. The judges will also consider ideas for new projects.

Prizes for the winners in each category include a trip to the award ceremony, which will take place in Barbados, in April 2000, as well as up to £2500 to support the project. The closing date for entries is October 31.

NetAid concert's new record
Cisco Systems, the worldwide leader in networking for the Internet, has announced that the Internet broadcast of the NetAid concert in Geneva, London and New Jersy on October 9, set a new world record for the largest Internet broadcast event for a single day.

More than 2.4 million streams of the NetAid concert were seen on www.netaid.org. The concert served as the kick-off for NetAid, a long-term initiative developed by Cisco and the United Nations Development Programme to help eradicate extreme poverty.

HCL acquires FEC Singapore
HCL Infosystems Ltd has acquired FEC Singapore Pvt Ltd. HCL Infosys has invested Rs 6.78 crore in the acquisition. Underlying this move is the company’s focussed strategy for the building its revenue from IT services.

Expected to net over Rs 50 crore to HCL Insys turnover the next 12 months, the acquisition is another step for company in mapping out a long-term and sustainable growth path based on the high-margin, high-value-add IT services sector.

Cognizant Technology Solutions
Cognizant Technology Solutions Corporation, an e-business and applications management outsourcer, has been chosen as the best small company by Forbes magazine’s list of “200 best small companies” appearing in November.

Cognizant delivers high-quality, cost-effective, full life-cycle solutions to complex software development, maintenance and re-engineering problems.

The company’s area of expertise include data warehousing, web enabling, Internet, object-oriented development, client-server and legacy systems.

HP launches next generation printers
Hewlett-Packard India has launched next generation `true-to-original’ photo quality printer and printing technology that signal a new era in the thermal inkjet technology.

The DeskJet 970Cxi professional series colour printer is based on a new thermal inkjet platform - HP PhotoREt III Colour Layering Technology - that combines the best everyday printing with the ability to produce breathtaking photos, vivid colour graphics and crisp black text.

The printer is the fastest photo-quality 2400 dpi printer. It includes an auto duplexer providing automatic two-sided printing and a manual print cancel button to stop print jobs.

It features HP’s new PhotoREt III printing technology,which combines smaller drop size and vibrant links with improved fade resistant to produce fast, outstanding print quality in all modes and all media, including realistic photo images.

HP Colorsmart III technology allows the printer to automatically deliver sharper, clearer, more vivid colour output. With parallel port and universal serial bus ability that provides plug and play capacity to computer peripherals, it makes set up a breeze. The printer costs around Rs 24,900 and ships with an array of bundled software.

—R. Suryamurthy/Gaurav Chaudhury