Indian Science Day is on Feb 28
Colours of roses, gemstones
by D.P. Singh
Colour is an inseparable part of the Nature. Almost everything around us can be identified by a colour. The colours displayed by the flowers of various species of flowering plants are of the most varied nature. Colour is the sensation experienced by an observer when he views the material under study.

Sonic electricity
A New York company is devising a way to generate electricity from a furnace. Using thermoacoustic technology originally conceived by scientists at Los Alamos National Laboratory, engineers at Clever Fellows Innovation Consortium (CFIC) in Troy have built a device for water-based heating systems that converts sound energy into electricity.

Science Quiz
by J. P. Garg

Life in new millennium
A new book titled “Predictions” compiles what the world’s 30 great minds have to say about life in the new millennium.

Asteroid hazard
It is night. The sky is clear and studded with twinkling stars. A couple of planets also shine brilliantly. Occasionally, a shooting star makes a streak across the darkness. We know what it is. A tiny mass of rock whirling in space, which on entering earth’s atmosphere heats up and catches fire. Harmless though, because most of them get burned away mid-air before hitting the surface of earth. Not quite.

Hydrogen from pond scum

CALIFORNIAN scientists have claimed that they had found a way to “grow’’ hydrogen gas from pond scum. A small commercial pool of algae could one day produce enough fuel to power a dozen cars for a week.

Hydrogen is the commonest element in the universe but expensive to make. It has to be extracted from methane, natural gas. But hydrogen burns with oxygen to produce water, which makes it the cleanest fuel of all.

Tasios Melis, a biologist at the university of California, Berkeley, told the American Association for the Advancement of Science meeting that he had found a metabolic switch that could make the microscopic alga Chlamydomonas reinhardtii react with sunlight to make quantities of hydrogen.

Berkeley and Prof Melis’s partners at the national renewable energy laboratory in Colorado have taken out a patent on the process. So far only small-scale cultures of the algae have been tested. “I guess it is the equivalent of striking oil,’’ said Prof Melis. “It was unbelievable.’’

Algae were among the first of the planet’s inhabitants, and would have evolved in the very different atmosphere of early earth. Certain types of algae have been known for decades to produce traces of hydrogen as they grew in sunlight. But no one had been able to make the yield rise to anything worth collecting.

The breakthrough was the discovery of a molecular switching process which could turn off the cell’s usual photosynthetic apparatus, and direct the cell to use its own stores of energy, with hydrogen as a byproduct. The switch is, reportedly, simple to activate. It depends on the absence of sulphur from the nutrients on which the algae will grow. Without sulphur there is no photosynthesis. To keep going the cells have to turn on another fallback energy source which releases hydrogen.

“They are utilising stored compounds and bleeding hydrogen just to survive,’’ Prof Melis said. “It’s probably an ancient strategy that the organism developed to live in sulphur-poor anaerobic conditions.’’

The researchers grew the algae using the sun’s energy, allowing the organisms to build up their carbohydrate stores. Then they transferred the microbes into sulphur-free bottles and waited while the algae consumed the remaining oxygen.

Within 24 hours the algae switched to their ancient emergency process and began to leak hydrogen to the top of the bottles. The plants could keep the process going for four days before they went back to normal photosynthesis to build up new reserves of hydrogen. Two or three days later, they could be tapped again.

Every litre of the culture yielded an hourly average of three millilitres of hydrogen. The scientists believe they could increase the yield 10-fold. They expect to see hydrogen-generator plants developed for small-scale use and for industry.

“We thought we would get trace amounts, but we got bulk amounts,’’ Prof Melis said. “Hydrogen is so clean burning that what comes out of the exhaust pipe is pure water. You can drink it.’’

(Guardian)

Indian Science Day is on Feb 28
Colours of roses, gemstones
by D.P. Singh

Colour is an inseparable part of the Nature. Almost everything around us can be identified by a colour. The colours displayed by the flowers of various species of flowering plants are of the most varied nature. Colour is the sensation experienced by an observer when he views the material under study.

Colour means different things to different people. To a physicist colour is matter of wavelength, which he can measure. A physiologist looks at the colour in terms of neural responses in the eye and the brain. a naturalist tries to discern clues to survival in terms of colour. for a painter, colour provides a means of expressing feelings and the intangible — in the form of works of art.

Sir C.V. Raman — one of the greatest experimentalists of the 20th century won Nobel Prize in Physics in 1930 for his epoch-making research, known as Raman Effect. He also did a lot of research work in the field of “The Colours of Roses and Gemstones”. Some of the interesting results obtained by him in this field are listed below.

Raman tried to ascertain the nature of pigments present in the rose petals, which absorb the light rays incident on them. He also studied the nature of rays, which escape such absorption and emerge as diffused light determining the observed colours.

Using a spectroscope, he revealed that roses exhibiting vivid colours such as scarlet, red or crimson completely absorb most of the visible spectrum allowing only limited regions of it to escape as diffused light. Similar observations with less vividly coloured roses (such as cream, pink, salmon, vermilion, mauve and lilac or the multicolured roses such as scarlet-yellow, or red-white) indicate only the parts of the spectrum suffering the greatest measure of absorption.

The in vitro study of the pigments extracted from the rose petals by organic solvent revealed many interesting results. The alcoholic extract from yellow roses exhibits an absorption, which covers the short-wave end of the spectrum and extends a little beyond the blue up to about 515 nm (1 nm-10-9 metre). The acetone extract from a rose of deep red colour exhibits three distinct lines in the yellow, green and blue-green region of the spectrum of light.

The factor, which is different for the roses of different colour, is the quantity of pigmentary material present in the petals. Examination of pink roses has revealed the greater absorption in the green sector of the spectrum between 500 nm and 550 nm.

The quantity of a pigment in rose petals determines the amount of absorption/diffusion of the colours of the incident light. The substantial quantity of pigment present causes the light to escape absorption only at the extreme red of the spectrum and the rose appears as a deep crimson. With less pigment available, wavelength upto about 600 nm could escape absorption and the colour of the rose appears as bright red. When the quantity of the pigment is still smaller, wavelengths between 570 nm and 600 nm commence to appear and the colour of the rose would alter from red to scarlet. With further diminution of the quantity of pigment available, the colour of the rose in diffused light alters from scarlet to orange.

To find the answer of such questions as why is emerald green, why is ruby red and why is sapphire blue, Raman examined gemstones also Raman reported that the rich green colour characteristic of emerald is exhibited by numerous pieces of beryl. The light transmitted through polished beryl exhibits the characteristic green colour of emerald. Spectroscopic studies confirmed the presence of observable transmission in the wavelength range between 450 nm and 500 nm. The results obtained with the beryl crystal were confirmed with a fine piece of emerald of gem quality, which exhibited a deep green colour.

Raman observed that when a collection of corundum and rubies is placed under the ultra-violet lamp the rubies exhibit a characteristic red glow and can be easily separated from the collection. He also reported that some rubies exhibit a purple colour. These rubies showed a strong absorption in the region of wavelength between 560 nm and 590 nm of the yellow sector in the spectrum of light. The spectral behaviour of these rubies closely resembles that of the purple flowers.

Rubies, which appear red, owe their colour to the existence of absorption covering both the yellow and green sector of the spectrum. Blue coloured flowers exhibit a strong absorption of the yellow colour of the spectrum. A similar behaviour is found to be exhibited by blue sapphire. On the basis of his research, Raman reported that the colours of gemstones exhibit features, which are in complete accord with those observed in the realm of flowers.

Sonic electricity

A New York company is devising a way to generate electricity from a furnace. Using thermoacoustic technology originally conceived by scientists at Los Alamos National Laboratory, engineers at Clever Fellows Innovation Consortium (CFIC) in Troy have built a device for water-based heating systems that converts sound energy into electricity.

The device consists of an oval pipe filled with helium that’s attached to a magnet-carrying piston mounted on springs. When the flame in a furnace burns gas, it also heats up the helium molecules. These molecules, in turn, begin to vibrate faster and generate sound waves in the pipe. The waves drive the piston, which resonates with the gas and moves the magnets past iron coils to produce electricity.

According to John Corey, founder of CFIC, the company’s prototype unit generates 500 watts of electricity continuously — that’s enough power to satisfy about half of a typical home’s electrical needs at any given time, although a connection to the utility grid would still be necessary. Says Corey: “The bigger the unit, the more it costs. The 500 to 1,000 watt range seemed the most economically prudent for a typical one family home.”

The device would be built into a furnace, increasing the gas needs of the furnace by around 7 per cent. But this extra gas generates electricity very efficiently — three to four times as efficiently as the local utility, which suffers losses in the distribution of power. It also features another inherent benefit: If the power grid is knocked out by, say, a storm, the unit would still generate enough electricity to maintain power in the home. The downside: price. The thermoacoustic device adds about 50 per cent to the cost of a typical furnace.

CFIC is now testing a prototype. If all goes as planned, the company will put the unit through field tests within a year. That will most likely happen in Northen Europe, where the price of electricity ranges between 15 and 30 cents per kilowatt-hour (compared with an average of approximately 8.4 cents in the United States) and where water-based heating systems are quite prevalent. At that cost of electricity, Corey estimates the device would pay for iteself within three years.

— Popular Science

Science Quiz
by J. P. Garg

1. India has recently announced its plans of an anti-ballistic missile system that will aim to destroy enemy missiles in flight. What kind of radiation beam can be possibly used in such a system?

2. Just as fingerprints are specific to each person, “atomic finger prints” are specific to each element by which the element can be identified. (For instance, some jewellers test the purity of gold by this method.) What are these “atomic finger prints” actually?

3. The newly-repaired US Hubble Space Telescope was back in action recently and it took pictures of a dying star that is 5,000 light years away. What name has been given to this star?

4. Butter gets spolied earlier while pure ghee can be stored for a much longer period. Can you state the reason?

5. About 30.000 varieties of this flower of different sizes and colours occur in nature throughout the world, of which about 1600 are available in India. The shapes of some species can be identified with that of a bird, monkey, tooth-brush, bitter gourd, ladies’ dresses or even a pair of Punjabi ‘jutties.’ Which flowers are we talking about?

6. Some animals adopt a sleep — like condition to protect themselves against cold and scarcity of food during winter and live on the fat stored in the body. What is this condition called in which body temperature decreases and heartbeat and breathing rate slow down?

7. If you were a student of histology, what would you be studying in living organisms?

8. First observed by English scientist Robert Hooke in 1664, the Great Red Spot has varied in size and colour over the years. Where is it found and what is it actually?

9. Hi-fi sound recording and reproduction systems have the minimum of distortion and the electronic components and circuits used in these systems are of very high quality. What does the term hi-fi stand for?

10. This French mathematician is known for his mean value theorem and a method for finding the maxima and minima for several variables. A function used in classical mechanics is also named after him. Who was this mathematician who became a professor at the age of 19 years?

Answers

1. Laser beam 2. Spectral lines of elements 3. Eskimo Nebula 4. Presence of water in butter facilitates growth of microbes. 5. Orchide 6. Hibernation 7. Structure of TISSUES 8. On the planet Jupiter; an atmospheric condition 9. High-fidelity 10. Luis Joseph Lagrange.

Life in new millennium

A new book titled “Predictions” compiles what the world’s 30 great minds have to say about life in the new millennium.

Well known writer Umberto Eco, economist J K Galbraith, feminist Andrea Dworkin have all put on their diversified ideas in the book. Editor of “Predictions”, Sian Griffiths says the compilation is “hugely exciting” and its timing at the close of millennium will interest more and more readers.

Arthur C Clarke, in this unusual compilation predicts that in 2010 Prince Harry will become the first member of the royal family to fly in space, while US feminist Elaine Showalter thinks that the 21st century will bring “new paranoias, new hysterias, new conspiracy theories and new imaginary illnesses”.

A leading IT professional believes that the ‘chip’ take control of all human actions, with people reading each other’s mind without speaking.

British scientist Susan Greenfield thinks world will only become “a society of restless, unimaginative individuals”.

Asteroid hazard

It is night. The sky is clear and studded with twinkling stars. A couple of planets also shine brilliantly. Occasionally, a shooting star makes a streak across the darkness. We know what it is. A tiny mass of rock whirling in space, which on entering earth’s atmosphere heats up and catches fire. Harmless though, because most of them get burned away mid-air before hitting the surface of earth. Not quite.

Some of them did manage to survive in the past and hit the earth because they were large enough. The impact of collision is believed to have been so great that it wiped off majority of living species at that time. Dinosaurs are believed to have gone extinct by this calamity. The 195-km-diameter crater Mexico’s Yucatan Peninsula is thought to be created by the impact of an asteroid. Although these are events of distant past there are some recent ones which have left their mark and not forgetting the cases of near misses, which could have been cataclysmic too.

It is difficult to know beforehand if an asteroid is heading towards our earth. In some cases, astronomers could know only when the thing swished past the earth, just missing it by half a million kilometres! Yes, even such distances that are large by territorial standards, amoung to only a hairbreadth by astronomical standards. And the explosion with an asteroid a few hundred metres across, would release enough energy that the whole stockpile in nuclear arsenals of the world cannot equal it.

Asteroids normally from a belt between the orbits of Mars and Jupiter and are thought to be remains of a gigantic collision between two planet-like heavenly bodies. They revolve around the sun, but their orbits are not that stable, primarily because of their small masses and under a slight gravitational perturbation, they go astray, only to be attracted by other heavier planets. In other words, though they move according to laws of physics, yet they are a traffic hazard, as far as we humans or, in general, life on earth is concerned.

Apart from asteroids, comets are the other scary objects in the sky which pose the same level of threats. The difficult with both of these objects is their large number, unknown trajectories in space and possibly intersecting orbits with the earth. There are millions of asteroids and we know only about a few thousand of them.

Gene Shoemaker, noted geologist/astronomer was the first to alert the world to the hazard posed by asteroids and comets. Although over a period of two decades, there has been an increased activity in asteroid hunting, still we are far from feeling safe. The strategy is to find new such objects in the sky, compute their orbits and identify the threat if it is there. If some object is heading towards us and is likely to collide after some years, we can plan how to tackle it and avert the danger.

The task of confronting the falling object is easier, if we know about its intentions at the earliest. The idea is then to send a warhead tipped rocket, which will collide with the object in the far out space and will succeed to deflect it off its normal path. In other words, we will send a traffic policeman which will teach this object how to move on heavenly roads. However, the later we come to know that an asteroid is hostile, more expensive it becomes to ward it off, as now the energy required in the deflection process multiplies at a faster rate. And if the explosion is great, the outcoming splinters will be going in all directions and can pose a new danger.

This brings us to the problem of what the nature of anti-asteroid missile should be. Some scientists advocate nuclear warheads, but there is a quite a voice of opposition. We do not want more N-weapons under whatever excuse! Yes, why don’t we make use of the exisiting ones? Secondly, the kind of deflecting explosion is to be decided by the nature and composition of the incoming object, like if it is solid or dense, or puffy? That would decide if it has to be a surface or subsurface explosion.

Definitely, the funding agencies and governments have to be convinced as to the urgency of the danger. That has been an uphill task. Is the danger real, or is it exaggerated, the skeptics mumble. Well, the world did watch the spectacular crashings of the comet Shoemaker-Levy onto the surface of Jupiter, which created craters of the size of earth. We should be able to extrapolate this evidence to the possible fate of earth. Needless to say, if in future, we are able to save life on earth from such a smashing hit, many perplexing issues about relevance of space exploration as well as the advanced weaponery, which currently seems to threaten life itself, will far naturally into perspective.

— Ramandeep Johal