Boost to India’s space marketing drive
by Radhakrishna Rao
The successful launch of India’s multipurpose domestic spacecraft INSAT-IIE on April 3 by means of an Ariane booster from Kourou launch-pad in French Guyana has given a big boost to India’s plan to consolidate its gains in the multimillion dollar global space market.

Music of spheres and space
by Dinesh Kumar
You worship your favourite god daily and pray to him to shower grace on you and keep your family, free from all evils. But has he ever replied to your prayers? Have you ever heard the sounds of “guru”, “shani”, “mangal” or “surya”?

New source of cells for transplant
US researchers have grown stem cells — cells that can give rise to a variety of tissues —from living nerve tissue for the first time ever, reports Reuters.

Science Quiz
by J. P. Garg

Earthquakes and their prediction
by Himank Kothiyal

EARTHQUAKE is an abrupt, violent shaking of the earth caused by the release of energy stored within rocks. This energy, built up over thousands of years, is vented out within seconds. Earthquakes occur when two plates collide, or slide past each other. The abrupt movement of plates releases an incredible amount of energy in the form of waves, which behave like sound waves and water waves. Many earthquakes are too small to be felt by humans. Others have caused wanton destruction of life and property, as is amply borne out by the recent Chamoli quakes and the after-quakes still striking terror in the Garhwal region.

It is estimated that over one million earthquakes rock the earth annually. Unbelievable, but true. Earthquakes measuring over 6 on the Richter scale are believed to be major quakes. An earthquake measuring 6 is said to be 10 times stronger than an earthquake measuring 5 on the scale, while that of magnitude 9 is 10,000 times more powerful. By any parameters, the Chamoli quake at 6.8 is definitely a major one.

The entire Himalayan region, indeed India, is believed to be prone to frequent earthquakes and is known to be situated in what is known as the “seismic belt”. Another common knowledge is the fact that the Indian and Eurasian continental plates are continually converging, though the rate of convergence of the plates may be a matter of debate. It is generally believed that the rate of convergence continues at the rate of 5 cm/year. In fact, the Himalayas resulted due to the collision of the Asian and Indian sub-continental plates about 50 million years ago.

Even today, large segments of faults of Himalayas are active, registering sporadic or intermittent movements. Certain areas where stress accumulates along segments for long period, release the stress suddenly and violently. The Latur experience and the recent Chamoli quakes bear ample testimony to the fact that the “changing face of the earth” continues to be as restless as ever.

WHY EARTHQUAKES OCCUR?

Plate tectonics has long been a veritable area of concern and has been rightly associated with the occurrence of earthquakes. Movement of the earth’s plates, coupled with their bending and squeezing against each other, exerts untold pressure on the rocks. It is believed that this convergence of the plates, is in the main, responsible for the sudden upthrusting of the Indian shield rocks beneath the Himalayan rocks.

In geological terms, an earthquake is the manifestation within and on the earth’s surface of sudden movements of active faults and thrusts. These movements result from a release of strain energy accumulated along geological faults, which have been moving since the earliest geological times. While the process of stress accumulation is a slow and a long drawn-out process, that of stress release is completed within seconds — or even in the batting of an eyelid. The seismic energy is released through faults alongside the plate boundaries, which after extensive research have been well-identified.

Over the millions of years, the belt of deformation, as a result of the convergence of the plates, has shifted southwards. Factors like underground water and temperature do go a long way in exerting strain on the rocks. Metamorphosis weakens the rock because water increases the total volume, pulling the rock in both directions, thereby tearing the rock apart. Rock layers have a certain elasticity, but when the pressure becomes unbearable, the rock layers move, producing a fault-line, along which the earthquake waves travel. The rupture in the rocks coupled with the movement of the layers of rocks produces earthquakes. The waves fan out in all directions, resembling the act of the ripples of waves being produced when a stone is thrown into a pond.

The question that arises is how does the strain energy in rocks accumulate? It is mainly caused by relative changes in the position of particles, at greater depths as well as at the ground surface, which is in turn caused by the sharp changes in temperature and other agents of atmospheric change. An interesting point to note in this regard is that most of the earthquakes — nearly 95 per cent, occur in depths shallower than 15 km.

Seismologists have pointed out that records from an earthquake made around the world changed radically once the event was more than a certain distance away. As an example they note that at about 105 degrees in terms of the angle between the earthquake and the seismograph at the centre of the earth, this change takes place. After 105 degrees the waves disappeared almost completely. The area beyond 105 degrees distance forms what is known in seismological parlance as a “shadow zone”.

TYPES OF SEISMIC WAVES

There are two types of seismic waves — P waves and S waves. Both these waves behave differently, depending on the material they contain and travel and refract through both fluids and solids. Compression waves are known as P waves or Primary waves, by virtue of the fact that they are the first to arrive on the surface of the earth. They are the fastest waves, travelling at speeds upto 14,000 m.p.h. at the surface and over 25,000 m.p.h. in the core of the earth.

Shear waves or S waves, as they are popularly known, reach the surface shortly after the P waves and are hence also known as Secondary waves. These waves travel at about half the speed of P waves. S waves can move only through solids and due to this property of theirs can travel in the crust and mantle of the earth. The third type of waves are the Surface Waves and are the most destructive of the three waves. Although they are much slower than both P and S waves, S waves can only travel along the surface of the earth. These waves are further sub-divided into — Love waves and Rayleigh waves. While the former move very much like the S waves, Rayleigh waves travel very much in the same way, as waves behave in water and have a circular pattern to their movements.

Seismic waves, travelling from the interior of the earth cannot be pinpointed in time and space. It is well-known that fracture zones could extend upto 700 km, or even more. On an average, the rupture or stress travels along the fault lines at a velocity of 3/3.5 km.

PREDICTION

Though at present there is no sure-shot way to accurately predict earthquakes, “forecasts” of the locations and magnitudes of some large earthquakes can be made. The recurrence of quaking experiences with a monotonous regularity has prompted man to undertake extensive studies of the interior of the earth. Geologists in general, and seismologists, in particular, have been leaving virtually no stone unturned, to see to it that the earthquakes may be predicted with a reasonable degree of accuracy. But barring a Chinese attempt at successful prediction of earthquakes, earthquake prediction continues to pose a challenge to the scientists. The billion dollar question — is earthquake prediction really possible ? The answer is — yes and no. The location and magnitudes can be predicted, though accurate pinpointing of the date and time may be as elusive as ever. Most large earthquakes occur along fault lines around the Pacific Ocean. It is said that the Atlantic Ocean is growing wider by a few inches annually, while the Pacific is shrinking as the continental floor beneath the Pacific Ocean is being pushed beneath the Pacific Rim continents. Fault lines due to the sliding of plates could be a factor, but there could be other factors too, which need extensive research.

Precursors normally can forebode an earthquake. The need of the hour is to be alive to the slightest clue offered. Usually, fault lines, strains and knots are given such overwhelming weightage that other factors are either lost sight of, or underestimated. In this regard, “hydro-chemical precursors” — such as marked changes in water levels, artesian well flow, eruption of underground geysers and concentration of gases play an important role. It is believed that in most cases, escape of gases has a major part to play either before or after a quake. Hydro-chemical precursors had been used to accurately predict the 1975 Haicheng earthquake in China.

The successful Haicheng prediction could be replicated for future predictions. Long-term prediction forms the first stage of the model, based on statistical analysis. During the second stage, medium-term prediction is made, in which scientists start monitoring the changes in geophysical precursors, based on the rates of change, properties of rocks and the region affected. The medium term predictions have to be constantly revised for a regular monitoring of the changes in the geophysical precursors. Based on a monitoring of these precursors, like changes in the level of ground water, short-term predictions have to be made.

A latest theory doing the rounds is that subterranean forces build up strains in the crustal rock which then is manifested in the earthquakes, which denote the timing of the fracture of that rock. Even eye-witness accounts claim that gas eruptions normally precede an earthquake. Though release of gas could well be a natural phenomenon, human activities such as extraction of oil and gas from deep inside the earth could also be partly responsible for building up the strain. Similarly, building of dams, mining/quarrying, nuclear testing could also trigger earthquakes.

Geologists have also found out that disposal of fluid waste material by injecting them deep into the earth under very high pressures could cause a release of strain energy in the rocks and are even exploring the feasibility of utilising fuel injection method to release the pent up energy, more so in perennially active fault zones or seismically active regions. There is also growing evidence that earthquakes can be predicted by measuring electric currents in earth’s crust.

Morphostructural zoning is carried on the basis of the distribution of epicentres and is used to indicate blocks and knots. These blocks and knots are then intricately studied, but their distribution pattern is so wide and extensive, that identification of all the blocks and knots is nearly impossible. Moreover, identification of all active faults and determining their potential for earthquakes is a major problem confronting seismologists.

However, several experiments have been carried out in the direction. A notable experiment was the South Indian strain measuring experiment, with the avowed objective of distinguishing regions undergoing local deformation from that of regions with relative stability. The initial results of the experiment were quite exciting. Similarly, in Germany, a sophisticated seismic system designed in mid-1992 to detect earthquakes and underground nuclear tests was completed. The German Experimental Seismic System (Geress) was part of international tests to determine of seismic monitoring equipment could be used to ensure compliance with nuclear non-proliferation treaties.

Besides, if earthquake prediction is to be a reality in the near future, the apparatus too has to be updated and brought at par with the technological changes in other spheres. To this end, using space imageries and aerial photographs, updating of the entire national seismic network, replacement of old seismographs by new broad-based digital systems are encouraging steps in the direction. The ‘strain fields’ all over the country are being monitored round the clock. The networking is so intricate that control points have been established at every 50-60 km.

The nature and character of seismic waves and our knowledge of what is going on beneath the earth’s surface may still be too scanty for us to be able to accurately predict earthquakes. However, the day is certainly not far off when earthquakes will be as predictable as forecasting rain and other weather-related phenomena.

Boost to India’s space marketing drive
by Radhakrishna Rao

The successful launch of India’s multipurpose domestic spacecraft INSAT-IIE on April 3 by means of an Ariane booster from Kourou launch-pad in French Guyana has given a big boost to India’s plan to consolidate its gains in the multimillion dollar global space market. For, as many as 11 C-band transponders onboard INSAT-IIE have been leased out to the Washington based satellite communications consortium Intelsat for a period of 10 years. This will fetch India $100-million in foreign exchange. It is for the first time that Intelsat has looked beyond its own fleet of satellites to augment the range of services offered by it.

And some time next month, India will make yet another foray into the global market for launching small satellites when the fully Indian Polar Satellite Launch Vehicle (PSLV) will orbit a German and South Korean satellites as piggyback payloads from Sriharikota High Altitude Range (SHAR) on the eastern coast of India. The success of the PSLV mission will help India give a practical shape to the agreement it had earlier entered into with Arianespace — a Paris-based space transportation company that markets the services of Ariane class of vehicles — for a common, joint strategy for launching small satellites. Under the deal either India or Arianespace could take up the order for launching small satellites depending on who can launch it first.

According to Didier Aubin, marketing and sales director of Arianespace, PSLV is a reliable system and no customer would have any problem with the fact that they can be launched by either Ariane or PSLV. The four-stage PSLV, powered by alternate liquid and solid fuel stages, is designed to launch a one-tonne class satellite into a polar orbit.

India hopes to promote PSLV as a cost-efficient launcher for orbiting lightweight satellites into a low earth orbit. A booming expansion forecast for the low earth orbit satellite networks dedicated to global personal communications services in the years ahead would help India promote PSLV in a big way in the global launcher market place. PSLV has also been booked by a Belgian outfit for launching its 100-kg Proba satellite in the near future.

Once India’s own cryogenic fuel driven Geosynchronous Satellite Launch Vehicle (GSLV) — now in the final stages of development — gets ready for routine orbital missions, India can confidently enter into the market for launching heavier class communications spacecraft. The three stage GSLV equipped with an upper cryogenic fuel state is designed to orbit 2.5 tonne class communications satellites into a geosynchronous orbit — 36,000 km above the euquator where a satellite appears stationary in relation to earth. The maiden flight of GSLV is expected to take place sometime next year.

The Bangalore based Antrix Corp, which was set up in 1992 with the objective of facilitating international marketing of Indian space capabilities and expertise, hopes that geostationary launch market would be a major hope for India in the future.

Obviously, India has managed to create its own niche in the booming global market for satellite resources data. The US based Space Imaging EOSAT, a major worldwide distributor of satellite resources data has tied up with Antrix Corp for the direct reception, distribution and marketing of value-added data from IRS constellation of satellites to the international customers. The network of international ground stations set up to receive, process and market IRS data products in different countries is now expanding. Six international stations — Neustralitz in Germany, Norman in USA, Bangkok in Thailand, Japan, Dubai and S.Korea — have all been receiving IRS data. Additional ground stations in Australia and Saudi Arabia are in the final stages of completion. Proposals for more IRS ground stations at Alaska and Equador are getting ready. International customers have found the data from IRS series of spacecraft to be as good and sharp as the data derived from the would class satellites of similar capability. Indeed IRS spacecraft has been described as a “jewel in the crown”

According to the latest Annual Report of the Indian Space Dept, supply of satellite hardware to companies overseas, including pressure transducers and fill and drain valves, has been undertaken. During the year telemetry, command and ranging station along with S-band support for on-orbit control of Afristar (one of the three satellites of Worldspace) has been established in Bangalore. Afristar has been launched and the station is now in operation.

In the area of satellite technology, India hopes to team up with major global players for the supply of components and subsystems. In the long run India hopes to build and supply satellites of varying categories to the international customers on a turnkey basis.

On another front, the market for telecommunications satellites for private sector service provider is also being tapped by Antrix. A contract has been signed with an Indian company for providing consultancy services for its satellite project aimed at owning and launching a satellite as an Indian registered satellite system. Negotiations are underway for marketing of telecommunication satellites jointly with leading spacecraft manufacturers.

Music of spheres and space
by Dinesh Kumar

You worship your favourite god daily and pray to him to shower grace on you and keep your family, free from all evils. But has he ever replied to your prayers? Have you ever heard the sounds of “guru”, “shani”, “mangal” or “surya”?

These gods in the form of planets of stars never talk to you but “shower” the “music” on earth. This music is called “music of spheres” by the astronomers because of spherical shape of these celestial bodies.

Our space is filled with all kinds of radio waves. The celestial bodies emit their own radiowaves. These radiofrequencies are received by antennae which have been raised by astronomers all over the world. When these radio frequencies are converted to audio waves to connect them with the loud speakers, we really have fun. Our milky way (Akash Ganga) produces incessant hiss the sound of a snake. Milky way is not a spherical body and we (our solar system) are a part of it. The cosmic broadcasts of Jupiter (Guru or Vrihspati) create a deep grumble that sounds as it were the legendary voice of thunder god himself. What is good Vrihspati complaining about? Perhaps he says, ‘O man! What have you done to this pious earth by your insane deeds?: And what about ‘Sun’? ‘He’ sighs intermittently. Because of its continuous burning? May be. But all the celestial bodies can not be heard since their emitted frequency falls out of the audible range of 20,000 cps.

Unlike astronomers, some space physicists adopt a T type simple antenna and concentrate their research in the 20 kilohertz range. This frequency range is called ELF/ VLF range (see “sound of space and safety of satellites, Science Tribune, Aug 27, 1998) when these waves are converted into audible waves and connected to a loudspeaker, we hear not only whistling of different kinds but also the sound of a snake.

Lion’s roar has also been heard by space physicists. An earth orbiting space satellite OGO 5 recorded some peculiar waves in space in March’ 68. When these electromagnetic waves were heard on an audio device, the scientists were taken aback. They were listening to the roar of a lion. These waves have frequency of 100=200 Hz but voltage of upto 3v. Now a tenth class science student can easily understand the difference between the fluttering of a bee and a lion’s roar (Fig. 1).

Chorus can also be heard from these space broadcasts. These are either received in the early morning (morning chorus) or late evening. Morning walkers can easily understand that morning chorus is nothing but chirping/singing of birds in the forests (Fig. 2). These signals have been frequently recorded in India, too, at space laboratories of BHU, Varanasi, Gulmarg, Nainital observatories and earth station Bichpuri (Agra). Whistling tones and chorus have their source of generation anywhere between 600-64000 km above earth but lion’s roar is produced only in magnetosheath, a region 15 Ro above it (Ro is earth radius of 6372 km).

Somebody may ask whether we can hear Nadbrahm (Brahmnad or Anhad Nad) i.e. the divine music. Yes and that too without any instrument. But then one should have love and faith in classical music (remember Einstein, Dr. Raja Ramanna or Dr. A.P.J. Adbul Kalam). Be fearless and go to open fields or jungle at dusk. Your ears will be hearing Anhad Nad. Yes, Nadbrahm is the sound of quietness. In the last you will like to say that physics is concerned with not only man and matter but music and metaphysics too.

— The writer is from the Deptt. of Physics, F.G.M. Govt. College, Adampur (Hisar).

New source of cells for transplant

US researchers have grown stem cells — cells that can give rise to a variety of tissues —from living nerve tissue for the first time ever, reports Reuters.

Such a handy source of the elusive stem cells might make it easier to cultivate them for transplants to treat brain diseases such as Parkinson’s and spinal cord injuries, the researchers said.

David Anderson and colleagues at the Howard Hughes Medical Institute in Pasadena, California, used a method that has been used in the past to isolate stem cells from the blood — which are used to treat a range of diseases including leukaemia and sickle cell anaemia.

Blood stem cells give rise to all the different kind of cells in the blood, including immune cells that fight infection and cancer. They can replace cells destroyed by harsh cancer treatment, a study published in the journal Cell says.

Science Quiz
by J. P. Garg

1. “A physician who fails to enter the body of a patient with the lamp of knowledge and understanding can never treat diseases”. Name the ancient Indian Ayurvedic physician who said this more than 20 centuries ago. Name also the book in which he described in detail anatomy of the human body and many common ailments suffered by humans.

2. Scientists fear that a surge of solar flares may shut down power grids and burn up satellites during late 1999 and early 2000. What is a solar flare? What can cause this type of damage?

3. An increase in the wavelength of light emitted by an astronomical object moving away from the earth can be used to estimate the velocity of the object. What is this increase in wavelength called and which effect is used to make this measurement?

4. We call earth our mother for its myriad life-supporting blessings to mankind. On which date is World Earth Day observed to focus global attention to preserve natural resources of earth.

5. Petroleum can be extracted from certain types of plants. Which chemicals are mainly contained in the latex of these plants?

6. What provides to the scientists a record of life that existed long ago? What is the study of such records called?

7. Which international organisation is officially recognised throughout the world for defining and maintaining the standard units of measurements in science? Where are its headquarters? Where are the prototypes of these units kept in India?

8. LEDs are now being replaced by LEPs in many electronic appliances such as cameras, televisions and computers. What is LED? What is LEP?

9. Glauber’s salt is generally used as a laxative in constipation. What is this salt chemically?

10. Name the only bird that builds its nest entirely with its saliva.

ANSWERS

1. Charaka; Charaka — Samhita, 2. A sudden brilliance of small areas of sun’s surface, A sudden outburst of radiations and charged particles from a solar flare produces immense heat by interaction with earth’s magnetic field, 3. Red shift; Doppler effect, 4. April 22, 5. Long chained liquid hydrocarbons, 6. Fossils; Plaeontology, 7. International Bureau of Weights and Measures; at Sevres, near Paris, at National Physical Laboratory, New Delhi, 8. Light emitting diode; Light emitting polymer, 9. Sodium sulphate decahydrate, 10. Swift.

How the nose knows
US and Japanese researchers believe they know how the nose knows.

Research published in the journal Cell shows that the nose uses a series of overlapping receptors to tell the difference between, for example, the aromatic smoke of a wood fire and the pungent odour of a burning electrical wire.

For years, researchers have been puzzled by the fact that though the nose only has about 1,000 types of odour receptors, most people can detect subtle differences in the aromas of thousands of substances.

Linda Buck of Harvard University and her colleagues from the Life Electronics Research Centre in Amagasaki, Japan, discovered that a single receptor can be stimulated by lots of aromatic chemicals.

Each chemical stimulates its own unique pattern among these 1,000 receptors, a pattern known as a receptor code.

Their work suggests an answer to the mystery of why a chemical’s smell can change so drastically if that chemical is altered only slightly. For example, a chemical called octanol has an orange or rose scent; but adding an atom of carbon and oxygen in the right place gives it a rancid odour.

That slight change is enough to stimulate a different pattern of receptors in the nose, creating a very different smell sensation, Buck said.

Sixteen receptors responded to octanol, she found, but 21 were stimulated when carbon and oxygen had been added to create the rancid octanoic acid.

“This explains something that has puzzled people for a long time,” she said.

It also suggests why a chemical’s odour can go from flowery to putrid as its concentration increases. “A change in the concentration of an odourant can result in a change in its receptor code,” the researchers concluded.

The work may also help explain why different people perceive the same odours differently.

Microbattery for microsurgery
Japanese scientists at the University of Tokyo have developed an enzyme-based microbattery which would enable microrobots to perform surgery inside the body.

Microsurgery techniques enable robots to be implanted within the human body. These robots can be directed remotely to a particular site. Once reached they release their cargo of drugs or perform the surgical feat before self destruction.

Though modern micromachining technology helps develop such tiny robots, the main problem is an electrical power supply which the robots will have to carry with them. The new biocatalytic cells are likely to be a promising candidate for this purpose.

By connecting a few such tiny cells in series, the Japanese group has developed an integrated enzyme battery. All individual cells are fabricated on a single silicon water, and the electrical power output of this battery has been found to be several watts, according to a report in the journal Trends in Biotechnology.

Though organic compounds do not break efficiently on an electrode surface, the Japanese team has adopted a slightly different approach to make these cells functional.

They use glucose as the enzyme’s substrate along with biocatalysts such as methanol dehydrogenase and formate dehydrogenase. Another group of chemicals called mediators (such as phenazinium methosulfate or tetrazolium) are used to break down the substrate.

Though these cells are able to provide high voltage, they have problems of lifetime and stability which the scientists hope to address in future.

Gene linked with obesity
Researchers have identified a gene that seems to affect not only a predisposition to diabetes, but a tendency to get fat.

Mice lacking the gene can eat and eat without gaining weight or getting the symptoms of diabetes, which is strongly linked to a high-fat diet and being overweight.

If people have the same gene, it could be a good target for drugs to treat not only diabetes, but also obesity, the researchers reported in the journal Science.

The gene is known as PTP-1B, for protein tyrosin phosphatase. Like all genes, animals get one copy from each parent.

Scientists at the Merck-Frosst Centre for Therapeutic Research in Quebec studied mice that had two copies of the gene — which mice normally have — and compared them to mice genetically engineered to lack either one or both copies of the gene.

They fed the mice a hugely fattening diet for ten weeks.

“On a high-fat diet the mice (with one or no copies of the gene) were resistant to weight gain and remained insulin-sensitive, whereas the (normal) mice rapidly gained weight and become insulin-resistant’” the researchers, who included a team at McGill University, reported.

Insulin resistance is the hallmark of type-II diabetes, which affects more than 130 million people world wide.

Already the fourth main cause of death in many countries, diabetes causes complications that kill 2.8 million people around the world every year.

At least four genes have been associated with a tendency to diabetes, and several genes have been linked with the tendency to put on weight.